A Multicentre, Double-Blind, Randomised, Non-Inferiority Trial of a Novel Single-Injection Intra-Articular HMDA-Cross-Linked Hyaluronate Gel for Knee Osteoarthritis.

: This Phase 3, randomised, double-blind, multicentre trial evaluated the efficacy and safety of a novel hyaluronic acid hydrogel cross-linked with hexamethylenediamine (HMDA-HA) compared to a conventional 1,4-butanediol diglycidyl ether cross-linked HA (BDDE-HA) in patients with mild-to-moderate knee osteoarthritis (OA). : A total of 223 adults (mean age 63.5 years; 167 women) with Kellgren-Lawrence (KL) grade I-III knee OA were randomised 1:1 to receive two intra-articular injections of HMDA-HA or BDDE-HA at baseline and at 24 weeks.

Frequent complications of deficient patellae after component removal in 1.5-stage exchange arthroplasty for periprosthetic joint infection.

Purpose: To compare the complication rates between deficient patellae (remnant patellae after component removal) and non-resurfaced patellae after 1.5-stage exchange arthroplasty for periprosthetic joint infection and identify risk factors for complications of deficient patellae.

Methods: Complications in 76 deficient patellae (group D) and 41 non-resurfaced patellae (group N), with a minimum follow-up of 2 years after 1.

Impact of a Unilateral High Tibial Osteotomy With a Large Correction on Functional Lateral Acetabular Coverage of the Hip Joint.

Background: Changes in limb length and coronal pelvic tilt, which occur along with changes in limb alignment, may affect the functional lateral acetabular coverage of the hip joint under weightbearing conditions.

Purpose: To analyze the functional lateral acetabular coverage after unilateral closed-wedge and open-wedge high tibial osteotomies with a large wedge correction of ≥10 mm.

Study Design: Cohort study; Level of evidence, 3.

Postoperative Decrease in Bone Marrow Lesion Associated With Better Clinical Outcomes Following Medial Open-Wedge High Tibial Osteotomy.

Purpose: To assess serial changes of preoperative bone marrow lesion (BML) following medial open-wedge high tibial osteotomy (MOWHTO) up to 2 years and evaluate whether postoperative change of BML affected patient-reported outcome measures (PROMs) at 2 years' follow-up. Factors related to the postoperative changes in BML also were evaluated.

Methods: The current study retrospectively assessed prospectively collected data of consecutive patients between December 2016 and March 2018 who underwent MOWHTO for symptomatic knee osteoarthritis with varus malalignment (≥5°) and a minimum 2-year follow-up.

Surgical accuracy of coronal and sagittal alignment in conventional closed-wedge high tibial osteotomy after computer-assisted surgery experience.

Background: Although intraoperative navigation can improve the surgeon's proficiency, no studies have analyzed postoperative outcomes of high tibial osteotomy (HTO) after computer-assisted surgery (CAS) experience. The present study compared the clinical and radiographic results between conventional and CAS closed-wedge (CW) HTOs after CAS experience.

Methods: Each of the 50 conventional and CAS CW HTOs performed by single surgeon between 2015 and 2017 were included.

Learning curve for robot-assisted knee arthroplasty; optimizing the learning curve to improve efficiency.

The introduction of robot-assisted (RA) systems in knee arthroplasty has challenged surgeons to adopt the new technology in their customized surgical techniques, learn system controls, and adjust to automated processes. Despite the potential advantages of RA knee arthroplasty, some surgeons remain hesitant to adopt this novel technology owing to concerns regarding the cumbersome adaptation process. This narrative review addresses the learning-curve issues in RA knee arthroplasty based on the existing literature.

Predictors of Recurrent Flexion Contracture after Total Knee Arthroplasty in Osteoarthritic Knees with Greater Than 15° Flexion Contracture.

Background: This study aimed to analyze the risk factors that predict recurrent flexion contracture (FC) after total knee arthroplasty (TKA) in osteoarthritic knees with FC ≥ 15°.

Methods: Data from a consecutive cohort comprising 237 TKAs in 187 patients with degenerative osteoarthritis, preoperative FC ≥ 15°, and a minimum follow-up period of 2 years were retrospectively reviewed. Preoperative FC was corrected intraoperatively from 0° to 5°.

Costal chondrocyte-derived pellet-type scaffold-free autologous chondrocyte implantation provided acceptable mid-term outcomes in osteochondral defects with up to 10-mm depth.

Purpose: To evaluate clinical, radiographic, and magnetic resonance (MR) results of costal chondrocyte-derived pellet-type scaffold-free autologous chondrocyte implantation (CCP-ACI) in osteochondral defects (ODs) up to 10-mm depth during 5 years of follow-up.

Methods: Ten patients with CCP-ACI performed in ODs with depth up to 10 mm were retrospectively analyzed. The minimum follow-up period was 5 years.

Aseptic survival of the 1.5-stage exchange arthroplasty for periprosthetic joint infection was acceptable when using an autoclaved femoral component and a new polyethylene insert.

Purpose: To investigate the aseptic survival of 1.5-stage exchange arthroplasty for periprosthetic joint infection (PJI) after total knee arthroplasty (TKA).

Methods: Eighty-eight cases of 1.

Clinical Efficacy and Safety of the Intra-articular Injection of Autologous Adipose-Derived Mesenchymal Stem Cells for Knee Osteoarthritis: A Phase III, Randomized, Double-Blind, Placebo-Controlled Trial.

Background: Intra-articular injection of autologous culture-expanded adipose-derived mesenchymal stem cells (ADMSCs) has introduced a promising treatment option for knee osteoarthritis. Although the clinical efficacy and safety of ADMSCs have been reported, the treatment remains controversial owing to the small sample sizes and heterogeneous osteoarthritis grades in previous studies.

Purpose: To assess the efficacy and safety of intra-articular injection of ADMSCs as compared with placebo in alleviating pain and improving functional capacity in a large sample of patients with knee osteoarthritis of Kellgren-Lawrence (K-L) grade 3.

Corrigendum to "Infection and Instability Increasing the Risk of Patella Baja and Pseudo-Patella Baja after Revision Total Knee Arthroplasty".

[This corrects the article on p. 71 in vol. 15, PMID: 36778990.

Similar Midterm Outcomes of Total Knee Arthroplasties with Anterior and Posterior Tibial Slopes Performed on Paired Knees at a Minimum Follow-up of 5 Years.

A small posterior tibial slope (PTS) is generally recommended in posterior stabilized (PS) total knee arthroplasty (TKA). An unwanted anterior tibial slope (ATS), which can affect postoperative results, may be created in PS TKA because of the inaccuracy of surgical instruments and techniques, as well as high interpatient variability. We compared midterm clinical and radiographic results of PS TKAs with ATS and PTS performed on paired knees using the same prosthesis.

Additional anteromedial staple fixation prevents changes in the posterior tibial slope in retrotuberosity bi-planar open-wedge high tibial osteotomy.

Purpose: To compare the changes in posterior tibial slope (PTS) between retrotuberosity biplane open-wedge high tibial osteotomies (RT-OWHTOs) with and without additional anteromedial staple fixation.

Methods: Seventy-nine and 77 cases of RT-OWHTOs without (Group N) and with (Group S) additional staple fixation, respectively, were retrospectively reviewed. All procedures were performed using a locking spacer plate.

Infection and Instability Increasing the Risk of Patella Baja and Pseudo-Patella Baja after Revision Total Knee Arthroplasty.

Background: Patella baja with patellar tendon shortening due to traumatic or ischemic injury is a widely known complication after primary total knee arthroplasty (TKA). Pseudo-patella baja may arise from the elevation of the joint line after excessive distal femoral resection. The maintenance of original patellar height is important in revision TKA because postoperative patella baja and pseudo-patella baja can cause inferior biomechanical and clinical results.

Use of Grafts on an Open Gap Is Advantageous for Preventing Correction Loss in 1-Week Staged Bilateral Open-Wedge High Tibial Osteotomies.

One-week staged bilateral open-wedge high tibial osteotomies (OWHTOs) can be a safe procedure, with the added advantage of fast functional recovery, cost saving, and reduced hospital stay. However, there can be concerns about correction loss after 1-week staged OWHTOs because high loading is inevitably applied to osteotomy sites during postoperative weight bearing. Although leaving the osteotomy site with no grafts is possible in OWHTOs, the use of grafts can provide additional stability to the osteotomy site and prevent correction loss.

Fixed distal femoral resection with a valgus cutting angle of 3° is more appropriate in intra-articular valgus deformity than juxta-articular valgus deformity in total knee arthroplasty: a retrospective single center study.

Background: The traditionally recommended fixed valgus cutting angle (VCA) of 3° is used as the standard method in total knee arthroplasty (TKA) for valgus deformity. The accuracy of distal femur cutting can be affected by the type of valgus deformity because the intramedullary rod for distal femoral resection can become impinged on the femoral cortex. The purpose of this study is to analyze the accuracy and precision of a VCA of 3° in mechanical alignment in TKA for valgus deformity, based on the type of the deformity.

Medial proximal tibial resorption after total knee arthroplasty according to the design of the cobalt chrome tibial baseplate.

Purpose: A new tibial baseplate of the cobalt-chrome (CoCr) prosthesis has an enhanced design with additional cement pockets and undersurface with increased roughness compared with the original baseplate. This study aimed to compare the incidence of medial proximal tibial resorption (MPTR) in total knee arthroplasties (TKAs) with the original and new CoCr tibial baseplates.

Methods: Each of 200 posterior stabilized TKAs with the original (Group O) and new (Group N) CoCr tibial baseplates with a minimum follow-up period of 2 years were retrospectively reviewed.

Mid- to Long-Term Outcomes After Medial Open-Wedge High Tibial Osteotomy in Patients With Radiological Kissing Lesion.

Background: Although medial open-wedge high tibial osteotomy (MOWHTO) is the treatment of choice for patients with mild to moderate osteoarthritis with varus malalignment, concerns about inferior outcomes in patients with preoperative radiological kissing lesion (RKL) remain.

Purpose: To compare the mid- to long-term clinical and radiological results and survivorship after MOWHTO in patients with versus without preoperative RKL.

Study Design: Cohort study; Level of evidence, 3.

Comparison of Clinical Outcomes for Patients Treated With Gradually Reducing Radius Versus Single-Radius Total Knee Arthroplasty Systems.

The choice of implant used for primary total knee arthroplasty (TKA) may have an impact on clinical outcomes. Clinical outcomes after TKA with gradually reducing radius implants (group G) vs single-radius implants (group S) were evaluated among Asian patients. This study included 541 patients (754 knees) in group G and 187 patients (275 knees) in group S.

Intra-articular Injection of Mesenchymal Stem Cells After High Tibial Osteotomy in Osteoarthritic Knee: Two-Year Follow-up of Randomized Control Trial.

Intra-articular injection of adipose-derived mesenchymal stem cell (ADMSC) after medial open-wedge high tibial osteotomy (MOWHTO) would be a promising disease-modifying treatment by correcting biomechanical and biochemical environment for arthritic knee with varus malalignment. However, there is a paucity of clinical evidence of the treatment. This randomized controlled trial (RCT) was aimed to assess regeneration of cartilage defect, functional improvement, and safety of intra-articular injection of ADMSCs after MOWHTO compared with MOWHTO alone for osteoarthritic knee with varus malalignment.

Closed-wedge high tibial osteotomy is more advantageous to maintain the correction than open-wedge high tibial osteotomy in osteopenic patients.

Purpose: To compare the incidence of correction loss and survival rate between closed-wedge and open-wedge high tibial osteotomies (CWHTO and OWHTO, respectively) in patients with osteopenic and normal bone.

Methods: Retrospective review was conducted for 115 CWHTOs and 119 OWHTOs performed in osteopenic patients [- 2.5 < Bone mineral density (BMD) T scores ≤ - 1] and 136 CWHTOs and 138 OWHTOs performed in normal patients (BMD T score > - 1) from 2012 to 2019.

Long-term survival of fully cemented stem in re-revision total knee arthroplasty performed on femur with diaphyseal deformation due to implant loosening.

Purpose: The study aims to analyze long-term clinical and radiographic results, and survival of re-revision total knee arthroplasty (TKA) using fully cemented stems performed on femurs with diaphyseal deformation.

Methods: Thirty-seven re-revision TKAs using fully cemented stems performed in femoral diaphyseal deformations, characterized as diaphyseal canal enlargement and cortex deformation due to aseptic loosening of previously implanted stems, between 2003 and 2015 were retrospectively reviewed. The mean follow-up period was 10.

How much preoperative flexion contracture is a predictor for residual flexion contracture after total knee arthroplasty in hemophilic arthropathy and rheumatoid arthritis?

Background: Although total knee arthroplasty (TKA) in hemophilic arthropathy (HA) or rheumatoid arthritis (RA) can improve functional ability, the postoperative range of motion (ROM) and prosthesis durability are reduced compared with those in osteoarthritic patients.

Aim: We aimed to compare (1) the pre- and postoperative flexion contracture after TKA in HA and RA, (2) the threshold of preoperative flexion contracture as a predictor of residual contracture > 15° after TKA, and (3) the survival rate.

Methods: Data from a consecutive cohort comprising 48 TKAs in HA and 92 TKAs in RA were retrospectively reviewed.

Mid-flexion laxity could be identified with continuous flexion-arc gap assessment in patients with a large preoperative convergence angle.

Purpose: To analyze the incidence of intraoperative mid-flexion laxity using continuous flexion-arc gap assessment, risk factors for mid-flexion laxity, and clinical results in navigation-assisted total knee arthroplasty (TKA).

Methods: Ninety posterior-stabilized TKAs were performed under navigation guidance for patients with degenerative arthritis and varus deformity. Intraoperatively, the gap between the trial femoral component and insert was evaluated in the navigation system with continuous flexion-arc gap assessment.

Intraoperative Assessment of Gap Balancing in Total Knee Arthroplasty Using Navigation with Joint Stability Graphs.

The purpose of this study was to assess continuous gaps in the replaced knee throughout the full range of motion (ROM) after total knee arthroplasty (TKA) using a joint stability graph, and to analyze the gap laxity in the mid-flexion range. Ninety-three TKAs were performed using imageless navigation with a joint stability graph. While positioning guides for each respective cut, the surgeon can safely preview the resection's impact for the resulting joint gaps and control the soft tissue balance at the knee flexion of 0° (extension) and 90° (flexion).